Generally, ferrite is a material represented by the molecular formula M.Fe.sub.2 O.sub.3 wherein M is principally a divalent metal ion and comprises a single or composite metal. The type of ferrite which is prevalently used today is composite ferrite comprising Mn (manganese), Ni (nickel), Co (cobalt), Fe (iron), Mg (magnesium) and Zn (zinc).
Such ferrite is used for the ferrite electrodes adapted for such applications as corrosion prevention, water treatment, etc., but recently request is rising for a ferrite electrode material which is capable of minimizing energy loss and suppressing high-frequency noise when a high-frequency current is applied to the ferrite electrode in certain uses.
The conventional ferrite electrode material containing the above-said metal elements was unsatisfactory, in regard of properties, to meet said request. The conventional ferrite material comprising said metal elements is either too high or too low in resistivity, too high resistivity resulting in a large energy loss while too low resistivity making it unable to suppress high-frequency noise, and thus the conventional ferrite material was incapable of realizing said both functions, that is, minimized or no energy loss and suppression of high-frequency noise, simultaneously.